Search results for " Systematics."
showing 10 items of 4820 documents
Subtropical streams harbour higher genus richness and lower abundance of insects compared to boreal streams, but scale matters
2018
Aim: Biological diversity typically varies between climatically different regions, and regions closer to the equator often support higher numbers of taxa than those closer to the poles. However, these trends have been assessed for a few organism groups, and the existing studies have rarely been based on extensive identical surveys in different climatic regions. Location: We conducted standardized surveys of wadeable streams in a boreal (western Finland) and a subtropical (south-eastern Brazil) region, sampling insects identically from 100 streams in each region and measuring the same environmental variables in both regions. Taxon: Aquatic insects. Methods: Comparisons were made at the scale…
First insights into female sperm storage duration in tardigrades.
2022
Female sperm storage is ubiquitous in the animal kingdom and it has been shown to be linked to several evolutionary processes, from postcopulatory sexual selection to dispersal. Here we report, for the first time, long-term sperm storage in females of the tardigrade Macrobiotus polonicus. Females, isolated after a short contact with a male, were able to use the stored sperm for up to 5 weeks (mean of 2 weeks), which translates to a considerable proportion of female post-mating longevity under controlled laboratory conditions (60% on average). Our study provides the first insights into the duration of sperm storage, an underexplored feature of the reproductive biology of tardigrades. Additio…
New genera, species and records of Phaneropterinae (Orthoptera, Phaneropteridae) from sub-Saharan Africa
2015
The results of the study of many specimens preserved in different European museums are reported. The tribe Terpnistrini Brunner von Wattenwyl, 1878 is resurrected. The distribution of the following species is enhanced: Pardalotaasymmetrica Karsch, 1896, Diogenadenticulata Chopard, 1954, Diogenafausta (Burmeister, 1838), Plangiopsisadeps Karsch, 1896, Poreuomenasanghensis Massa, 2013 and Tylopsiscontinua (Walker, 1869). Further, for their peculiar characteristics, two African representatives of the American genus Symmetropleura Brunner von Wattenwyl, 1878 are included in two new genera: Symmetrokarschiaafricana (Brunner von Wattenwyl, 1878), comb. n. and Symmetroraggeadirempta (Karsch, 1889)…
FMECA Application in Tomotherapy: Comparison between Classic and Fuzzy Methodologies
2022
Accident analysis in radiotherapy highlighted the need to increase quality assurance (QA) programs by the identification of failures/errors with very low probability (rare event) but very severe consequences. In this field, a Failure Mode, Effects and Criticality Analysis (FMECA) technique, used in various industrial processes to rank critical events, has been met with much interest. The literature describes different FMECA methods; however, it is necessary to understand if these tools are incisive and effective in the healthcare sector. In this work, comparisons of FMECA methodologies in the risk assessment of patients undergoing treatments performed with helical tomotherapy are reported. …
Towards a framework for assessment and management of cumulative human impacts on marine food webs
2015
Effective ecosystem-based management requires understanding ecosystem responses to multiple human threats, rather than focusing on single threats. To understand ecosystem responses to anthropogenic threats holistically, it is necessary to know how threats affect different components within ecosystems and ultimately alter ecosystem functioning. We used a case study of a Mediterranean seagrass (Posidonia oceanica) food web and expert knowledge elicitation in an application of the initial steps of a framework for assessment of cumulative human impacts on food webs. We produced a conceptual seagrass food web model, determined the main trophic relationships, identified the main threats to the fo…
The effects of grazing history, soil properties and stand structure on the communities of saprotrophic fungi in wood-pastures
2022
Wood-pastures are threatened anthropogenic biotopes that provide habitat for an extensive group of species. Here we studied the effect of management, grazing intensity, time since abandonment, historical land-use intensity, soil properties and stand conditions on communities of saprotrophic fungi in wood-pastures in Central Finland. We found that the proportion of broadleaved trees and soil pH are the major drivers in the communities of saprotrophic fungi in these boreal wood-pastures. In addition, tree species richness, soil moisture, historical land-use intensity and time since abandonment affected the communities of saprotrophic fungi. Current management or grazing intensity did not have…
Editorial: Chemical Ecology and Conservation Biological Control
2022
International audience
Sex Allocation Theory for Facultatively Sexual Organisms Inhabiting Seasonal Environments: The Importance of Bet Hedging
2018
Adaptive explanations for dormancy often invoke bet hedging, where reduced mean fitness can be adaptive if it associates with reduced fitness variance. Sex allocation theory typically ignores variance effects and focuses on mean fitness. For many cyclical parthenogens, these themes become linked, as only sexually produced eggs undergo the dormancy needed to survive harsh conditions. We ask how sex allocation and the timing of sex evolve when this constraint exists in the form of a trade-off between asexual reproduction and sexual production of dormant eggs—the former being crucial for within-season success and the latter for survival across seasons. We show that male production can be tempo…
Kin selection in interactions between gametes: Gamete competition, gamete limitation, and sex allocation
2023
Kin selection on one hand, and gamete interactions in post-ejaculatory sexual selection on the other are two major research themes that have risen to prominence over the past half century and have simultaneously developed into central fields of research in evolutionary biology. There is a natural connection between the two: when gametes interact with each other, very commonly many of them originate from the same parent and are thus siblings. For example, sperm competition will almost always involve competition between sibling gametes even if the interacting parents are not related to each other. If parents are related to each other, the relatedness between gametes increases further. Here we…
New Gynandromorph Records for Chirocephalus diaphanus (Branchiopoda, Anostraca, Chirocephalidae)
2021
We report and describe new Chirocephalus diaphanus Prévost, 1803 gynandromorphs from Tunisia and review the literature of anostracan gynandromorphy and other, possibly associated, somatic aberrations, with comments on their evolutionary significance. Our material has three specimens that are specifically deformed on the left side of the head.